Hi, Thanks for writing to Healthcaremagic. Let me explain you one by one. Surprisingly there are less studies or researches on this topic. Omeprazole is not know to cause any adverse effect on sperm count or fertility. Lisinopril is not having direct effect on sperm count but it effects fertility by following side effects-- -Decreased interest in sexual intercourse -inability to have or keep an erection -lack or loss of strength -loss in sexual ability, desire, drive, or performance. But these are rare side effects. Simvastin cause rarely erectile dysfunction. It is also shown in some studies that it reduce testeosterone levels which is required for sperm production. This may be the cause of reduced sperm count. You can discuss with your doctor to switch to alternative drugs if you encounter any of above side effects. Hope I have been helpful. Regards Dr. Ashish Verma